We propose research to study the effects of experimental myocardial ischemia on heart vascular exchange as determined by cardiac lymphatic transport of proteins, trace metals and enzymes. Two surgically prepared models will be used: an acute anesthetized cardiac lymphatic preparation and a chronic unanesthetized cardiac lymphatic preparation. A bypass cannula will be used to perfuse the left anterior descending coronary artery. The duration and extent of reduced coronary flow will be acheived by an external occluder on the cannula. Coronary sinus blood will be sampled. The effects of partial or total coronary occlusion on transport as evaluated by cardiac lymph flow and variation in content in lymph and blood will be correlated with resultant pathological changes. The transport effects in response to myocardial ischemia will be compared to alterations with cardiac lymphatic obstruction and following the administration of steroids, hyaluronidase and zinc. The results will be used to assess the clinical implications of these transport alterations in ischemia heart disease.